A 2-year-old child with a history surface of URTI, who died with signs of cardiopulmonary failure, has hyperemic right lung. In segments 2, 6, and 10 on the surface and on section there are irregular-shaped yellow airless foci, with their size varying from several millimeters to 1 cm. Microscopy shows that in theses alveoli, bronchioles and small bronchi contain exudate with predominance of neutrophils. What is the most likely diagnosis?